Access control for network slices of a wireless communication system

ABSTRACT

A base station for a wireless communication network comprising a plurality of logical radio access networks, wherein the base station is configured to communicate with a plurality of users to be served by the base station for accessing one or more of the logical radio access networks, and the base station is configured to selectively control the physical resources of the wireless communication network assigned to the logical radio access networks and/or to control access of the users or user groups to one or more of the logical radio access networks, wherein, during a first operation mode of the wireless communication network, the base station is configured to allow access of users or user groups of one or more of the logical radio access networks (e.g., eMBB, URLLC, eMTC), and wherein, during a second operation mode of the wireless communication network, the base station is configured to adaptively limit access of users or user groups to one or more of the logical radio access networks, and/or adaptively reduce a number of enabled logical radio access networks.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending U.S. patent applicationSer. No. 17/524,612 filed Nov. 11, 2021 which is continuation of U.S.patent application Ser. No. 16/459,463, filed Jul. 1, 2019, which inturn is a continuation of copending International Application No.PCT/EP2018/050100, filed Jan. 3, 2018, which is incorporated herein byreference in its entirety, and additionally claims priority fromEuropean Application No. 17150279.2, filed Jan. 4, 2017, which is alsoincorporated herein by reference in its entirety.

The present invention concerns the field of wireless communicationsystems, such as a mobile communication network. Embodiments of thepresent invention relate to the access control of network slicesimplemented in a wireless communication system.

BACKGROUND OF THE INVENTION

Conventionally, different services use a corresponding number ofdedicated communication networks, each tailored to the respectiveservice to be implemented. Instead of using a plurality of specificallydesigned networks, another approach, known as network slicing, may use asingle network architecture, like a wireless communication network, onthe basis of which a plurality of different services is implemented.

FIG. 1 is a schematic representation of a system for implementingdifferent services using the concept of network slices. The systemincludes physical resources, like a radio access network (RAN) 100. TheRAN 100 may include one or more base stations for communicating withrespective users. Further, the physical resources may include a corenetwork 102 having, e.g., respective gateways for connections to othernetworks, a mobile management entity (MME), and a home subscriber server(HSS). A plurality of logical networks #1 to #n, also referred to asnetwork slices, logical networks or subsystems, are implemented usingthe physical resources depicted in FIG. 1 . For example, a first logicalnetwork #1 may provide a specific service to one or more users. A secondlogical network #2 may provide for an ultra-low reliable low latencycommunication (URLLC) with users or equipment. A third service #3 mayprovide general mobile broadband (MBB) services for mobile users. Afourth service #4 may provide for a massive machine type communication(mMTC). A fifth service #5 may provide health services. Yet furtherservices #n, to be determined, may be implemented using additionallogical networks. The logical networks #1 to #n may be implemented atthe network side by respective entities of the core network 102, andaccess of one or more users of the wireless communication system to aservice involves the radio access network 100.

FIG. 2 is a schematic representation of an example of the wirelessnetwork 100 or wireless network infrastructure of the wirelesscommunication system of FIG. 1 . The wireless network 100 may include aplurality of base stations eNB₁ to eNB₅, each serving a specific areasurrounding the base station schematically represented by the respectivecells 106 ₁ to 106 ₅. The base stations are provided to serve userswithin a cell. A user may be a stationary device or a mobile device.Further, the wireless communication system may be accessed by IoTdevices which connect to a base station or to a user. IoT devices mayinclude physical devices, vehicles, buildings and other items havingembedded therein electronics, software, sensors, actuators, or the likeas well as network connectivity that enable these devices to collect andexchange data across an existing network infrastructure. FIG. 2 shows anexemplary view of only five cells, however, the wireless communicationsystem may include more such cells. FIG. 2 shows two users UE1 and UE2,also referred to as user equipment (UE), that are in cell 106 ₂ and thatare served by base station eNB₂. Another user UE₃ is shown in cell 106 ₄which is served by base station eNB₄. The arrows 108 ₁, 108 ₂ and 108 ₃schematically represent uplink/downlink connections for transmittingdata from a user UE₁, UE₂ and UE₃ to the base stations eNB₂, eNB₄ or fortransmitting data from the base stations eNB₂, eNB₄ to the users UE₁,UE₂, UE₃. Further, FIG. 2 shows two IoT devices 110 ₁ and 110 ₂ in cell106 ₄, which may be stationary or mobile devices. The IoT device 110 ₁accesses the wireless communication system via the base station eNB₄ toreceive and transmit data as schematically represented by arrow 112 ₁.The IoT device 110 ₂ accesses the wireless communication system via theuser UE₃ as is schematically represented by arrow 112 ₂.

The wireless communication system may be any single-tone or multicarriersystem based on frequency-division multiplexing, like the orthogonalfrequency-division multiplexing (OFDM) system, the orthogonalfrequency-division multiple access (OFDMA) system defined by the LTEstandard, or any other IFFT-based signal with or without CP, e.g.DFT-s-OFDM. Other waveforms, like non-orthogonal waveforms for multipleaccess, e.g. filter-bank multicarrier (FBMC), generalized frequencydivision multiplexing (GFDM) or universal filtered multi carrier (UFMC),may be used.

For data transmission, a physical resource grid may be used. Thephysical resource grid may comprise a set of resource elements to whichvarious physical channels and physical signals are mapped. For example,the physical channels may include the physical downlink and uplinkshared channels (PDSCH, PUSCH) carrying user specific data, alsoreferred to as downlink and uplink payload data, the physical broadcastchannel (PBCH) carrying for example a master information block (MIB) anda system information block (SIB), the physical downlink control channel(PDCCH) carrying for example the downlink control information (DCI),etc. For the uplink, the physical channels may further include thephysical random access channel (PRACH or RACH) used by UEs for accessingthe network once a UE synchronized and obtained the MIB and SIB. Thephysical signals may comprise reference signals (RS), synchronizationsignals and the like. The resource grid may comprise a frame having acertain duration, e.g. a frame length of 10 milliseconds, in the timedomain and having a given bandwidth in the frequency domain. The framemay have a certain number subframes of predefined length, e.g., 2subframes with a length of 1 millisecond. Each subframe may include twoslots of 6 or 7 OFDM symbols depending on the cyclic prefix (CP) length.The PDCCH may be defined by a pre-defined number of OFDM symbols perslot. For example, the resource elements of the first three symbols maybe mapped to the PDCCH.

The above described wireless communication system may be a 5G wirelesscommunication system which may allow network slicing. As mentionedabove, the logical networks or slices are implemented at the networkside 102, but there is also an effect on the radio access network 100.The resources provided by the radio access network 100 are sharedbetween the respective slices, for example, they are assigneddynamically by a scheduler of a base station. At the radio accessnetwork 100, for one or more of the slices #1 to #n, which may use adifferent numerology, respective logical radio access networks 114 ₁ to114 _(n) are defined. A logical radio access network defines for acertain slice the resources of the radio access network 100 to be used.For example, for one or more different services, in the frequencydomain, a certain subband or a certain number of carriers of the radioaccess network 100 may be used. In accordance with other examples, thephysical separation may be in time, code or spatial domains. In spatialdomain, separation may be performed using special beamformingtechniques. Such a separation may be used for services using differentnumerologies, e.g., different physical layer parameters such assubcarrier distance, cyclic prefix length, modulation or access scheme.For services using the same numerology different predefined physicalresource blocks may be used.

FIG. 3 is a schematic representation of a plurality of logical radioaccess networks or logical RANs 114 ₁ to 114 ₄, also referred to in thefollowing as RAN subsystems, for a wireless communication systemimplementing the logical networks or subsystems #1 to #4. FIG. 3 assumesservices implemented by respective subsystems #1 to #4 using differentnumerologies which are physically separated in the frequency domain.FIG. 3 schematically represents a part of physical resource grid to beused. Each of the logical RANs 114 ₁ to 114 ₂ to be used for a specificsubsystem #1 to #4 has assigned a certain bandwidth or a number ofcontinuous carriers in the frequency domain. In accordance with otherexamples, a service may have assigned multiple subbands or differentcarriers. FIG. 3 schematically represents the transmission of downlinkcontrol information 116 for the respective subsystems #1 to #4. Thecontrol information 116 for all of the subsystems #1 to #4 istransmitted only on the resources for the subsystem #3. The controlinformation 116 may include the control channels and control signals,e.g., the synchronization signals, the common reference symbols, thephysical broadcast channel, the system information, paging informationand the like. Instead of transmitting control information for each ofthe subsystems #1 to #4, the control information 116 is only transmittedonce on the resources of the subsystem #3. The subsystems #1, #2 and #4also listen to these resources to see whether any control informationform them is transmitted. In the example of FIG. 3 , the logical RANs114 ₁ to 114 ₄ are provided for specific subsystems #1 to #4, namely forsubsystems providing an enhanced mobile broadband (eMBB) service, anultra-low reliable low latency communication (URLLC), an enhancedmassive machine type communication (eMTC), or another service not yetspecified. Providing the control information 116 in a way as depicted inFIG. 3 is resource efficient as only one transmission is needed for allsubsystems #1 to #4, instead of transmitting separate controlinformation for each of the subsystems #1 to #4 via the respective thelogical RAN 114 ₁ to 114 ₄.

FIG. 3 refers to the resource sharing during the downlink. However, theresources may also be shared during the uplink. For example, during aconnection setup, the resources for the random access channel (RACH) maybe shared, e.g., like in the downlink also in the uplink the RACHinformation is only transmitted on the resources of the subsystem #3.For example, the control information 116 may indicate the common uplinkrandom access resources to be used for the random access procedure. TheRACH may be operated at relatively low load to avoid collisions and thusmultiple transmissions and added latency. For example, a four-step RACHprocedure may be used, as it is illustrated in FIG. 4 . In a radioaccess network, such as the one depicted in FIG. 2 , a UE, after sendingan uplink random access preamble {circle around (1)} in the uplink,monitors for a random access response message {circle around (2)} fromthe base station generated by the MAC layer and transmitted on theshared channel. Dependent on the cause of the RACH message, for example,an initial connection set-up using a radio resource control (RRC)connection request or a request for re-establishing a connection,different RRC messages may be sent in the uplink. Following the access,respective scheduled transmissions {circle around (3)} are performed.There may be a further response message {circle around (4)} from thebase station to resolve collisions with other UEs that may happen duringthe access procedure.

Mobile communication systems may also provide for an access control soas to control the access of UEs to the system, e.g., to the entiresystem or only to one or more cells of the system to avoid congestionand overflow. One mechanism is the so-called access class barring (ACB),in accordance with which certain cells limit access to certain classesof UEs. ACB is broadcast by the base station of the cell to control therandom access procedure. Other congestion control mechanisms, such as anRRC reject or a Non-access stratum (NAS) reject, may involve additionalsignaling at the RRC layer, the NAS layer or a higher layer. In such acase, the fully overloaded system may not even be capable transmittedsuccessfully such a control signaling, despite its usually highpriority. For example, in accordance with the LTE standard, ACB providesmeans to control access of regular devices with access classes 0 to 9,and to limit access to only special access classes, for example to:

special AC 11 Reserved for Network Operator special AC 12 SecurityServices (police, surveillance, etc.) special AC 13 Public Utilities(water, gas, electricity, etc.) special AC 14 Emergency Services specialAC 15 Network Operator Staff (maintenance, etc.)

AC 10 may control as to whether any emergency calls are allowed forregular devices or not.

There may be another congestion and overload control mechanisms definedat the radio and network levels. For example, the following admissionand overload control mechanisms are defined by the LTE standard:

Radio Rel.8 eNB Access Class Barring (idle UEs) Radio Rel.8 RRC RejectMessage (connected UEs) NW Rel.8 NAS reject message or data throttlingRadio/NW Rel.9 Service Specific Access Control (SSAC) Radio/NW Rel. 12Skip Access Class Barring for MMTel Radio/NW Rel. 13 Applicationspecific congestion control

In other wireless communication network systems, such as the 5G wirelesscommunication system, a single or common access control scheme may beused. As long as a wireless communication system operates under standardcircumstances, it is beneficial to share the resources among therespective logical RANs, as explained above, however, sharing resourcesamong the network slices may not be efficient in each and everysituation in which a network is operated.

SUMMARY

An embodiment may have a base station for a wireless communicationnetwork comprising a plurality of logical radio access networks,wherein: the base station is configured to communicate with a pluralityof users to be served by the base station for accessing one or more ofthe logical radio access networks, and the base station is configured toselectively control the physical resources of the wireless communicationnetwork assigned to the logical radio access networks and/or to controlaccess of the users or user groups to one or more of the logical radioaccess networks wherein, during a first operation mode of the wirelesscommunication network, the base station is configured to allow access ofusers or user groups of one or more of the logical radio access networks(e.g., eMBB, URLLC, eMTC), and wherein, during a second operation modeof the wireless communication network, the base station is configured toadaptively limit access of users or user groups to one or more of thelogical radio access networks, and/or adaptively reduce a number ofenabled logical radio access networks.

Another embodiment may have a wireless communication network,comprising: one or more base stations for a wireless communicationnetwork comprising a plurality of logical radio access networks,wherein: the base station is configured to communicate with a pluralityof users to be served by the base station for accessing one or more ofthe logical radio access networks, the base station is configured toselectively control the physical resources of the wireless communicationnetwork assigned to the logical radio access networks and/or to controlaccess of the users or user groups to one or more of the logical radioaccess networks wherein, during a first operation mode of the wirelesscommunication network, the base station is configured to allow access ofusers or user groups of one or more of the logical radio access networks(e.g. eMBB, URLLC, eMTC), and wherein, during a second operation mode ofthe wireless communication network, the base station is configured toadaptively limit access of users or user groups to one or more of thelogical radio access networks, and/or adaptively reduce a number ofenabled logical radio access networks; a plurality of user equipments;wherein the wireless communication network is configured to enable aplurality of logical radio access networks, and to provide a pluralityof physical resources for a wireless communication among a base stationand a plurality of users to be served by the base station.

Another embodiment may have a method in a wireless communication networkcomprising a plurality of logical radio access networks, wherein a basestation communicates with a plurality of users to be served by the basestation for accessing one or more of the logical radio access networks,the method comprising: selectively controlling, by the base station, thephysical resources of the wireless communication network assigned to thelogical radio access networks and/or controlling, by the base station,access of the users or user groups to one or more of the logical radioaccess networks wherein, during a first operation mode of the wirelesscommunication network, the base station allows access of users or usergroups of one or more of the logical radio access networks (e.g. eMBB,URLLC, eMTC), and wherein, during a second operation mode of thewireless communication network, the base station adaptively limitsaccess of users or user groups to one or more of the logical radioaccess networks, and/or adaptively reduces a number of enabled logicalradio access networks.

Another embodiment may have a non-transitory digital storage mediumhaving a computer program stored thereon to perform, when executed by acomputer, a method in a wireless communication network, the wirelesscommunication network comprising a plurality of logical radio accessnetworks, wherein a base station communicates with a plurality of usersto be served by the base station for accessing one or more of thelogical radio access networks, and the method comprising: selectivelycontrolling, by the base station, the physical resources of the wirelesscommunication network assigned to the logical radio access networksand/or controlling, by the base station, access of the users or usergroups to one or more of the logical radio access networks, wherein,during a first operation mode of the wireless communication network, thebase station allows access of users or user groups of one or more of thelogical radio access networks (e.g. eMBB, URLLC, eMTC), and wherein,during a second operation mode of the wireless communication network,the base station adaptively limits access of users or user groups to oneor more of the logical radio access networks, and/or adaptively reducesa number of enabled logical radio access networks.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be detailed subsequentlyreferring to the appended drawings, in which:

FIG. 1 is a schematic representation of a system for implementingdifferent services using the concept of network slices;

FIG. 2 shows a schematic representation of an example of the wirelessnetwork or wireless network infrastructure of the wireless communicationsystem of FIG. 1 ;

FIG. 3 is a schematic representation of a plurality of logical radioaccess networks for a wireless communication system implementing logicalnetworks;

FIG. 4 illustrates a conventional four-step RACH procedure;

FIG. 5 shows an embodiment for prioritizing eMBB operations over mMTCoperations during the daytime;

FIG. 6 shows on the left the situation of FIG. 3 assuming a regularoperation of the system, i.e., working in a first operation mode, and onthe right the configuration of the system when operating in a secondoperation mode, for example, in case of an emergency;

FIG. 7 shows an embodiment for implementing control access on the basisof additional access control information;

FIG. 7(a) and FIG. 7(b) show another embodiment for implementing controlaccess using a first operational mode executed during an initial attachof the UE, and a second operational mode once the UE is configured withadditional access control information by the network;

FIG. 8 shows an embodiment in which the system information blocks aresplit into general control information for all UEs, and additionalcontrol information for the different subsystems;

FIG. 9 shows a location specific group access in accordance with anembodiment of the present invention;

FIG. 10 schematically shows an access control hierarchy using a basicaccess control and a detailed access control in accordance withembodiments of the present invention;

FIG. 11 schematically shows an access control hierarchy with detailedaccess control information provided by the subsystems in accordance withembodiments of the present invention;

FIG. 12 shows a block diagram for the acquisition of system informationin accordance with an embodiment of the present invention;

FIG. 13 is a schematic representation for the isolation of controlsignals and channels for certain subsystems, such as a PPDR (publicprotection and disaster relief) subsystem;

FIG. 14 is a schematic representation of a plurality of logical radioaccess networks for a wireless communication system implementing logicalnetworks in the downlink and in the uplink;

FIG. 15 schematically shows the acquisition of system information forthe use of RACH resources;

FIG. 16 is a schematic view of a two-step RACH procedure in accordancewith an embodiment of the present invention;

FIG. 17 schematically represents an RRC state model for a wirelesscommunication system, such as a 5G system;

FIG. 18 is a schematic representation of a wireless communication systemfor communicating information between a transmitter and a receiver; and

FIG. 19 illustrates an example of a computer system on which units ormodules as well as the steps of the methods described in accordance withthe inventive approach may execute.

DETAILED DESCRIPTION OF THE INVENTION

In the following, embodiments of the present invention are described infurther detail with reference to the enclosed drawings in which elementshaving the same or similar function are referenced by the same referencesigns.

As mentioned above, when a wireless system operates regularly, the abovedescribed sharing of the resources is beneficial. However, there may besituations in which such sharing needs tighter control, for example, inresponse to specific events or at specific times. In accordance with thepresent invention the physical resources of the wireless communicationnetwork assigned to the logical radio access networks are selectivelycontrolled, and/or access of the users or user groups to one or more ofthe logical radio access networks is controlled. More specifically,embodiments of the present invention introduce a more flexible handlingof resources for an access control (first and second aspects) and forthe configuration of the RACH resources (third aspect).

In accordance with the first aspect, a subsystem specific access controlis described, and in accordance with the second aspect, the systeminformation is split into a first part, which is referred to as basicaccess control (BAC) and defines general access control parameters, andinto a second part, which is referred to as detailed access control(DAC) and defines subsystem specific access control parameters. Inaccordance with the third aspect a dynamic RACH resourcesharing/isolation is described. It is noted that all aspects andembodiments may be combined and used together, except they are mutuallyexclusive.

First Aspect

In accordance with embodiments of the first aspect of the presentinvention, the common downlink system information, for example, thebroadcast channel may be used to adaptively control access to therespective subsystems, via the associated logical radio access networks.

When the wireless communication system operates in a first operationmode, access to all of the subsystems may be allowed. When the wirelesscommunication system operates in a second operation mode, in accordancewith the inventive approach, the number of subsystems to which access isallowed and/or the number of users allowed to access the system may belimited. The access control may be performed by a base station of acell, when the wireless communication system is in the second operationmode in which access control is desired. For example, this may be thecase in an emergency or when specific events occur or at specific daysor times. Further, the wireless communication system may cover a largegeographical area, and the access control may not be needed in theoverall area covered but only in one or more subareas or cells in whichthe event occurred. In such a case, only the base stations serving thecells or defining a subarea may perform the inventive access control.Base stations in other areas may operate without the inventive accesscontrol, i.e., the resources are shared among all subsystemsimplemented. In the other areas, the system operates in the firstoperation mode, which may be a regular mode. In specific cases, such asnation-wide emergency cases, the entire wireless subsystem may operateon the basis of the inventive access control approach. When not all ofthe base stations or cells are operated in accordance with the inventiveaccess control approach, users at the edge of a cell or a subarea forwhich the limited access control is performed, may try to access thedesired subsystem in neighboring cells, provided this is allowed andsufficient connectivity is given.

As mentioned above, in accordance with embodiments, the switching fromthe first operation mode to the second operation mode may occurresponsive to predefined events, such as

-   -   emergency situations,    -   overload situations,    -   special events,    -   specific minimum requirements of one or more of the subsystems        operated, or    -   a certain day or time.

FIG. 5 shows an embodiment for prioritizing eMBB operations over mMTCoperations during the daytime. On the left, FIG. 5 schematicallyrepresents the access control during the nighttime, during which accessis allowed to all of the subsystems #1 to #4. During the daytime,however, control is restricted to subsystems #1 to #3. The physicalresources, which are assigned to the logical RAN 114 ₄ for the subsystem#4 during the night time, are assigned to the logical RAN 114 ₃ for thesubsystem #3 during the daytime, i.e., the mMTC subsystem is no longeraccessible. In accordance with embodiments, access control is achievedby no longer scheduling any resources for the radio access to thesubsystem #4, i.e., the logical RAN 114 ₄ is no longer present. Theembodiment of FIG. 5 is advantageous as it allows a delay un-criticalservice, as provided by the mMTC subsystem #4, to be temporarily barredso as to limit this service to a specific time, like the nighttime,during which the massive machine type communications may be performed.For example, sensors or machines which provide data that is not timecritical may be read out via the wireless communication system once aday. During the daytime, this allows for an increase in the availableresources that may be used for the other subsystems. In the embodimentof FIG. 5 , while the resources associated with the subsystems #1 and #2remain the same, the resources associated with the eMBB subsystem #3 areincreased.

In accordance with further embodiments, one or more of the respectivesubsystems may be further differentiated, for example, in terms ofdifferent service qualities of a service provided by the respectivesubsystem. For example, when considering the eMBB subsystem, someservices provided by this subsystem may include the transmission ofspecific data, such as video data, in different service qualities.Services may provide video content to users with a high quality so as tofulfill the user experience when downloading video information, whereasother services, such as security services, provide video informationwith a quality that depends, for example, on whether a specific eventneeds more details of the scene currently recorded or as to whether onlya surveillance to monitor an area for moving objects is performed.Dependent on such services, the subsystem may be further differentiatedinto bandwidth classes, and for different service qualities respectivebandwidth may be assigned so that the different service qualities may beprioritized. The specific access control class (AC class) may besignaled to the UEs together with additional information about the videoqualities available, which may be different for different users. Inother words, according to embodiments, to limit or suspend one or moreservices using the logical radio access network the base station mayselect for one or more users or user groups of a service a certainservice quality from different service qualities, like video quality,and/or bandwidth, and/or latency, e.g., in terms of number of resourcesgrants in a given time interval.

The embodiment as described with reference to FIG. 5 allows forgradually evacuating the wireless communication system such thatspecific services on existing connections may be scaled-down or eventerminated. This may be achieved by using specific signaling protocols.For example, in order to offload video users in case of emergencyevents, a signaling is provided to regular users to “stopstreaming/requesting new data” for example, by using a DASH SANDmessage. Further, if one or more of the subsystems demands a highercapacity, for example, in case a PPDR (PPDR=public protection anddisaster relief) UE requests high data rates without terminating othersubsystems, the DASH SAND message may be used in an existing DASHsession so as to scale down the video service. A similar mechanism maybe applied for other services, for example, to terminate or limitsoftware updates, e.g., sessions with online stores. The particular DASHSAND message may be triggered by a network entity, such as the HSS (homesubscriber register) the MME or the DANE (Dash Aware Network Element),or it may directly be triggered by the base station. In case scalingdown is not sufficient, the inventive approach for controlling accessmay completely shut down subsystems by admission control on otherlayers.

In the embodiments described above, it has been described that onespecific subsystem, like the mMTC subsystem #4, may be temporarilybarred. The invention is not limited to such embodiments. Othersubsystems may be barred dependent on other events, such as other timesor dates, on the basis of reoccurring events or in case of an emergency.In the latter case, an example for a subsystem that may be prioritizedover other subsystems is the PPDR subsystem. Such a subsystem may beprioritized over the other subsystems in case of an emergency, such as aterrorist attack or a disaster, so as to avoid overload situations inthe entire wireless communication system or in affected cells of thesystem. For example, all or most of the other subsystems may be shutdown so that access is only possible to the wireless communicationsystem by PPDR UEs, i.e., regular UEs may not be able to access thesystem anymore. In accordance with further embodiments, one or more ofthe subsystems, besides the PPDR subsystem, may remain operative;however, with a lower priority than the PPDR subsystem. For example, thesubsystem allowing emergency calls may remain operative; however, toavoid an overflow of the network and the blocking of RACH resources,emergency calls may only be allowed with a priority lower than anycommunication in the PPDR subsystem.

In the embodiments described so far, access control included the barringof one or more subsystems from access; however, in accordance withfurther embodiments, access control may also be achieved by graduallyreducing the number of UEs that are allowed to access one or more of thesubsystems via the respective logical RANs 114 ₁ to 114 ₄. The controlinformation 116 may signal to a UE a time period during which thesubsystem is not accessible, also referred to as a barring time, so asto inform the UE about the next time at which an access is possible. Therelated access barring back-off parameters may be subsystem-specificparameters. Further, the control information may indicate that aspecific subsystem, like the above described mMTC subsystem, isgenerally supported and that the UE requesting access to such a systemstays connected to the network; however, that access is temporarilybarred. Once the access is allowed again, the UE can immediately connectto the service provided by the respective subsystem. In accordance withother embodiments, in case the control information signals that theservice provided by a specific subsystem is generally supported buttemporarily not available, the UE may start a scan for other subsystemsproviding the same or similar services.

In accordance with the embodiments described so far, a specific event,such as a specific time, date was assumed to trigger the access control;however, in accordance with further embodiments, such events may bereoccurring events. For such reoccurring events an access schedule maybe provided as a part of the system information that is, for example,transmitted upon connection set-up via the system information to the UE.The access schedule may indicate, when considering the embodiment ofFIG. 5 , that during nighttime the mMTC subsystem #4 is available, butnot during the daytime. Another reoccurring event is, for example, thatpeople commute during the day and are in the office so that during thistime high-speed mobile broadband services as provided by the eMBBsubsystem #3 are needed, while during nighttime the needed eMBB capacitymay be decreased significantly, thereby freeing resources which may beused for another subsystem, e.g., for a URLLC communication in subsystem#2. In accordance with yet further embodiments, rather than providingthe access schedule as a part of the system information, it may also besignaled as part of the control information, for example, a dailyschedule about which subsystem is served at what time of the day, may besubmitted. Different schedules may be transmitted for different days,for example, weekdays may use a first schedule and weekend days may usea second, different schedule.

In the embodiments described above, access to one of the subsystems hasbeen barred; however, in accordance with further embodiments, theinventive access control may limit access to only one subsystem. Inaccordance with an embodiment, the subsystem #1 accessed via logicalradio access network 114 ₁ may be a PPDR subsystem. The inventive accesscontrol may limit access only to the PPDR subsystem #1 while barring allother subsystems #2 to #4. This is schematically depicted in FIG. 6 ,which shows on the left the situation of FIG. 3 assuming a regularoperation of the system, and on the right the configuration of thesystem in the second operation mode, for example, in case an emergencyoccurred. In FIG. 6 , responsive to switching the wireless communicationsystem or a part thereof into the second operation mode, access to thesubsystems #2 to #4 via the logical RANs 114 ₁ to 114 ₄ is no longerpossible. All resources are scheduled to the logical RAN 114 ₁ foraccessing the PPDR subsystem #1. Limiting access to one of thesubsystems is advantageous as, for example, in the PPDR subsystem #1mission-critical operations may need a higher bandwidth. For example, HD(high definition) videos may be transmitted permanently from a disasterarea or during a mission-critical operation. However, it is notefficient to reserve such a huge amount of resources permanently, whilesuch events may happen only rarely. Further, there is no need to reservethe amount of resources for the entire system permanently as, even incase such an event occurs, it is likely that it is only occurring in alimited region of the area covered by the wireless communication system.Thus, in such exceptional cases, the approach, as explained withreference to FIG. 6 , allows providing the PPDR subsystem #1 with asufficiently large transmission capacity, in case the exceptionalsituations occur. The outage of the general services to other UEs, insuch exceptional cases, may be acceptable.

In the above described embodiments, when specific services are disabledso as to free resources for high priority services, the base station mayredirect UEs from the currently used subsystem, which no longer providesthe service or provides the service with a reduced quality, to othersubsystems still providing the service. In accordance with embodiments,an inter-subsystem handover or redirection signaling to all UEsconnected to the subsystem is provided. For example, the UEs of asubsystem may form a group having a specific group or subsystemidentity. By signaling the group identity, all of the UEs currentlyconnected or making use of the specific subsystem may be identified andaddressed. The signaling may be sent via a paging channel or a commoncontrol channel, and part of the signaling may be information about thenew or target subsystem to which the UEs are redirected, such as thecarrier frequencies, cell identity, access technology type (like FDD orTDD), and/or subframe configuration details of the new subsystem nowproviding the service.

Now, further embodiments are described for realizing the inventivesubsystem based admission control in case of shared resources so as toallow providing resource sharing during a first mode of operation of thesystem or parts of the system, like a regular operation, and a secondmode of operation, like resource isolation, in exceptional cases. Theinventive access control may also be referred to as a basic accesscontrol (BAC) which may be realized in accordance with the subsequentlydescribed embodiments.

In accordance with a first embodiment of the BAC, the controlinformation 116 may include one or more bits, advantageously a singlebit. The control information provided by a base station to the UEs is toinform the UEs whether a certain subsystem is supported or not. Forexample, when considering FIG. 5 and FIG. 6 , the control informationmay include information as represented in the following table:

Indicator Meaning eMBB Support supported/not supported URLLC Supportsupported/not supported mMTC Support supported/not supported PPDRSupport supported/not supported

In accordance with a second embodiment of the BAC, the controlinformation 116 may include access control information, like a singlebit or multiple bits, which indicates that only certain devices, such asUEs or IoT devices, have access to one or more of the subsystems. Forexample, in case of one of the above mentioned events the wirelesscommunication system, at least in part, operates in the second operationmode. The following table shows an embodiment for a single bit accesscontrol information indicating that for specific subsystems onlyspecific UE types are allowed to access or not access, i.e., are barredor not barred.

Indicator Meaning Access Control for eMBB devices UE type barred/notbarred Access Control for URLLC devices UE type barred/not barred AccessControl for mMTC devices UE type barred/not barred Access Control forPPDR devices UE type barred/not barred

For example, in FIG. 6 a single bit may limit access to the system onlyto PPDR devices.

In accordance with other embodiments, the access control informationgiven in the table above may be used to block specific UE hardware orsoftware. In such a case, additional information may be signaled for theaccess control purpose, for example, the equipment type, such as theIMEI (international mobile equipment identity) or a software version(SV), for example, IMEI-SV. The access control in accordance with thisembodiment provides additional functionality included into the radiolayers at the UE and at the base station. Conventionally, the UE type isknown to the higher layers in the UE, for example, it may be stored onthe SIM (scriber identity module) card. In the network, UE type is alsoknown at the higher layer and may be stored in the HSS or the MME.However, conventionally, the UE type is not known at the radio layer ofthe UE, for example, at the radio resource control (RRC) layer. Inaccordance with embodiments, for implementing the access control on thebasis of the UE type during the connection set-up phase, the RRC layermay consider the UE terminal type during the access control procedure,and the UE RRC layer is informed about the parameter describing the UEtype. More specifically, the higher layer (e.g. NAS protocol) of the UEinforms the lower layer of the UE either during theconnection/call/session set-up phase, or the lower layer (e.g. RRCprotocol) may have stored this information from previous procedures, forexample, from an initial connection set-up.

In accordance with a third embodiment of the BAC, the controlinformation 116 may include access control information per subsystem.For example, a single bit or multiple bits may made be used to bar acomplete subsystem, as indicated in the table below. For example foreach subsystem of FIG. 5 and FIG. 6 a single bit indictor may beprovided in the control information 116 indicating that the respectivesubsystem is barred or not barred.

Indicator Meaning eMBB Access Control subsystem barred/not barred URLLCAccess Control subsystem barred/not barred mMTC Access Control subsystembarred/not barred PPDR Access Control subsystem barred/not barred

In accordance with this embodiment, for implementing the inventiveaccess control scheme, the UE radio functions, such as the RRC layer,are made aware of the subsystem that is to be accessed, which may beperformed in a way as described above with regard to the secondembodiment.

In accordance with a fourth embodiment of the BAC, the controlinformation 116 includes information, like one or more bits, to indicatethat additional access control information has to be obtained. Thesystem information that is broadcast to all UEs may be limited, however,when using only a limited number of bits, advantageously a single bit,the additional information that needs to be signaled is reduced. On thebasis of this additional information the UEs are requested to obtainadditional system information with additional control parameters beforeactually accessing the subsystem, e.g., via an associated logical RAN.The additional information, as is shown in the table below, indicates,e.g. in the system information, that prior to actually starting theaccess procedure, additional access class barring information is to beobtained and considered. The additional information to be obtained maybe the information described with regard to the first, second and thirdembodiments of the BAC.

Indicator Meaning Read Additional Access Class Barring Access allowedwithout additional Information* access barring information/Read *maybelimited to certain UE Types, additional access barring services orsubsystems information before accessing the system

FIG. 7 shows an embodiment for implementing the control access on thebasis of additional access control information. In FIG. 7 , a wirelesscommunication system is assumed which is similar to the one in FIG. 5and FIG. 6 ; however, only three subsystems #1 to #3 are implemented. Inthis embodiment, the PPDR subsystem #1, the URLLC subsystem #2 and theeMBB subsystem #3 are provided, which are accessed via the respectivelogical RANs 114 ₁ to 114 ₃. When compared to FIG. 5 and FIG. 6 , thecontrol information now includes first control information 116 a andsecond control information 116 b. For example, when system informationtransmitted, for example, via the SIB, the control information 116 a mayinclude a bit which, when being set, indicates that the wirelesscommunication system or at least part thereof operates in accordancewith the second operation mode. When the bit is set, a UE is not allowedto access the system right away, but needs to obtain additional accessclass barring information provided by the additional control information116 b. Like in the embodiments described so far, the additional controlinformation 116 for all of the subsystems may be transmitted only on theresources for one of the subsystems, in the depicted embodiment theresources of the subsystems #3.

In accordance with another embodiment a first operational mode, using,e.g., the access control based on BAC, is only executed during aninitial attach of the UE, see for example FIG. 7(a), while a secondoperational mode is used once the UE is configured with additionalaccess control information by the network, see for example FIG. 7(b).The additional access control information may be mapping information tomap a group identity, a subsystem identity, a certain device type orspecific services to a newly defined access category to be used in asecond operational mode of access control. This allows a flexiblemapping of various parameters to a single parameter that can be used foraccess control.

During the initial step, after receiving the basic system informationfrom the gNB (see message “0” in FIG. 7(a)), the UE may access thesystem on a first logical access network or default access network usinga first set of access parameters, e.g., a first or default accesscategory (see messages “1” and “2” in FIG. 7(a)). In this initial accessattempt the UE does not have a detailed network configuration such as anaccess category for access control. It may thus use a preconfiguredaccess category, a default access category or a configuration based onthe service type but not on the network slice. Once the access categoryis decided the UE reads the RRC System Information (see messages “3” and“4” in FIG. 7(a)), e.g., which access category is barred and which isnot barred, to get to know if it is allowed to access the base stationor not (see message “4” in FIG. 7(a)).

Once the UE is connected to the network, the network configures the UEwith additional control information 116 b (see message “5” in FIG.7(b)). The additional control information may include slice specificconfigurations as well as additional access control information such asthe mapping information to map a group identity, a subsystem identity, adevice type or a service type to an access category. As is shown in FIG.7(b), such control and mapping information may be provided by a higherlayer protocol such as the Non-Access Stratum protocol (NAS). By meansof NAS messages are exchanged between the UE and the next generationnetwork via the 5G base station.

After the UE is configured with the mapping information, the UE operatesin a second mode. In this mode the UE considers its newly assignedaccess category in the access control process (see for example FIG.7(b)). Before accessing the base station, e.g., due to a mobileoriginating call or session, once again the UE needs to identify theaccess category that is applicable for this specific access attempt (seemessages “0” to “5” in FIG. 7(b)). Due to the flexible configuration,there may be various criteria such as access to a specific networkslice, a specific service type, e.g., an emergency call, a specificterminal type etc. Once the access category is known the UE checks theRRC System Information whether this respective access category is barredor not. In accordance with embodiments, the Access Control may beexecuted.

As is depicted in FIG. 7(a) and in FIG. 7(b), one implementation of thisembodiment may use the NAS protocol at the UE to define an accesscategory for the access attempt, while the UEs RRC protocol at theaccess stratum performs the final barring check. This is done bycomparing the access category to the RRC System Information receivedfrom the base station indicating the access categories that are barredor are not barred. The barring check therefore involves interactionsbetween the UE NAS and RRC layer that are exchanged via primitives. Incase the system is barred temporarily the RRC may check a barring timingduring this process. In case the network slices are mapped to accesscategories, the network may control access to specific slices bychanging respective RRC system information in the base station.

In accordance with a fifth embodiment of the BAC, an access is onlyallowed if access control information of the subsystem has beenobtained. A subsystem is considered to be barred until the accesscontrol information has been obtained. The access control informationmay be provided using the one or more control information as describedabove in the first to fourth embodiments. In accordance with furtherembodiments, the access control information may be obtained viadedicated RRC control signaling. FIG. 8 shows an embodiment in which theaccess control information is split into general control information 116for all UEs and additional control information 116 ₁ to 116 ₃ for therespective subsystems #1 to #3. Like in the embodiments described sofar, the general control information 116 for all of the subsystems maybe transmitted only on the resources for one of the subsystems, in thedepicted embodiment the resources of the subsystems #3. The additionalcontrol information 116 ₁ to 116 ₃ for the respective subsystems #1 to#3 may be transmitted on the resources for the respective subsystem. Forexample, for each subsystem supported the general information 116 mayinform a UE about the resources, like the frequency band or thecarrier(s), to listen to for obtaining the additional controlinformation for the subsystem to which the UE wishes to connect.

This embodiment is advantageous as the additional access barringinformation 116 ₁ to 116 ₃ for the respective subsystem provides moredetailed information. For example, besides limiting access to thesubsystem, further limits with regard to accessible services, forexample, conversational services, or further limits with regard toallowed UE types, such as devices of security services, public utilitiesor staff of the network operator, may be provided. Also, when operatingthe system or parts thereof in the second operation mode, it may bebeneficial not to bar all other subsystems or all other services;rather, some services may still be allowed, for example, emergency callsfor public users.

In accordance with a sixth embodiment of the BAC, the controlinformation 116 may include an indicator that a public warning messageexists. The existence of such a public warning message may trigger a UEto read additional barring information, such as those described abovewith reference to the fifth embodiment. Public warning messages arebasically known in the 2G/3G/4G systems, for example, for issuingearthquake warnings or tsunami warnings. In the system blockinformation, for example, a bit may be provided that indicates thatfurther system information relating to the public warning message areavailable and may be read. In the table below, an example for theindicator is given. When activated or set, before granting access the UEneeds to read the additional access barring information, and on thebasis of this information access is finally granted or not.

Indicator Meaning Read Additional Public Warning Read/read notadditional access Message Information barring information beforeaccessing the system

It is noted that the access control in the warning or error indicatormessages may be combined so that, for example, in case an access isblocked, the user may get a message that indicates the cause for theblocking. The broadcast message content may include a message referringto an emergency situation, or an overload situation, or a certain eventat a certain date and for a certain duration, or changes in a serviceusing the logical radio access network, or a certain day and/or nighttime.

In accordance with a seventh embodiment of the BAC, the inventivecontrol access approach includes a system load indicator query for UEsof a specific subsystem. For example, when considering a PPDR subsystem,PPDR UEs may query the system load during the access phase so as toindicate the number of UEs/the percentage of cell load of PPDR UEs inthe cell. Based on this information, the PPDR UEs within the same zonemay connect to a master PPDR UE which is itself connected to thewireless communication system, for example, to a base station such as amacro base station or a micro base station. The master PPDR UE is alsoconnected to one or more slave PPDR UEs within the same coverage zoneand may communicate with these slave devices in a device-to-devicemanner, for example, over the PC5 interface. This approach isadvantageous as it allows multiple UEs of a specific type qualifying forthe specific subsystem to connect to the system via the master UE.

In accordance with an eighth embodiment of the BAC, the inventive accesscontrol approach may allow for a location specific access. For example,in public safety situations, ubiquitous access to the network may becrucial. Access to the network may be achieved via a direct connectionto the base station or via device-to-device (D2D) connections over adirectly connected UE, as indicated, for example, in the seventhembodiment described above. Even in the case of the seventh embodimentor in other situations, direct access to a base station may be limited,and access control information in the UE may force the UE to first checkif the connection via D2D with neighboring UEs may be achieved. FIG. 9shows an example for a location specific group access in accordance withthe eighth embodiment. FIG. 9 shows a cell including a base station eNBand a plurality of users UE that are directly connected to the basestation, as is indicated by the arrow “Uu”. In case one of the userswithin the cell recognizes that it is not possible to directly accessthe base station, in accordance with the inventive access control schemeof the eighth embodiment, the UE may include access control informationforcing the UE try to make a D2D connection, for example, via the PC5interface, to a neighboring UE. In FIG. 9 , such connections areindicated by the arrow “PC5”. This approach may be beneficial, forexample, when specific areas of the cell are crowded so that access tothe base station from this area of the cell is limited by the basestation to a reduced number of UEs. In such a case, to allow other UEsto also access the network, the UEs may connect to the base station viathe master UE. The information regarding the access control to be storedin the UE may indicate that an indirect connection is possible so thatwhen the respective information is enabled or a bit is set in theinformation block, the UE not in a position to make a connection to thebase station, tries to connect via D2D to directly connect to UEs, asindicated in the table below.

Indicator Meaning Indirect connection enforced Try connecting via D2D todirectly connected UEs.

The master user equipment may relay certain information from the logicalradio access network to one or more blocked slave users. The relayedinformation may include:

-   -   (1) relay control and/or data channels in the downlink        direction, or    -   (2) relay control and/or data channels in the uplink direction,        or    -   (3) both (1) and (2).

Second Aspect

In the embodiments described thus far, the new access control parametersdescribed above have been provided or introduced on a per-subsystembasis. However, the invention is not limited to such an approach;rather, in accordance with a second aspect of the inventive approach,the access control may be split into a first part, which is referred toas the basic access control (BAC), and a second part, which is referredto as the detailed access control (DAC). The BAC and the DAC may both bepart of the system information, e.g. in the SIB, provided to a UE whenconnecting to the system.

The BAC defines a first set of access control parameters, for example,those described above with reference to FIG. 4 to FIG. 9 . The BAC maybe part of the control information 116 described in the embodimentsabove, and may be delivered on the resources for one of the subsystems,also referred to as an anchor subsystem. The DAC defines a second set ofaccess control parameters. The DAC includes additional access controlparameters for one or all of the subsystems. In accordance withembodiments, the DAC for the different subsystems may be provided usingthe resources of the anchor subsystem. In accordance with otherembodiments, the DAC for a subsystem may be provided using resourcesassigned to the corresponding subsystem.

FIG. 10 schematically shows the access control hierarchy using a BAC anda DAC in accordance with a first embodiment of the second aspect of thepresent invention. The BAC and the DACs may be provided as part of thecontrol message 116 described above. The BAC 118 and a plurality of DACs120 ₁ to 120 ₃ for the subsystems is provided by using anchor subsystem.

Alternatively the Basic Radio Access Control (BAC 118) is part of theRadio Resource Control system information that is broadcasted, while thedetailed access control (DAC 120) is part of dedicated RRC signaling orpart of the Non-Access Stratum protocol. During the initial attachprocedure (see for example FIG. 7(a)) the BAC with a pre-configured ordefault DAC is used. This initial attach procedure may be performedbased on cell wide BAC system information without any dedicatedsignaling. Once the UE access is authorized, the UE will connect to thebase station and the network, which will provide additional detailedaccess control parameters (see for example FIG. 7(b)). Any followingaccess attempt may consider the BAC information together with thenetwork configured DAC information. This procedure allows for a fastinitial access with minimum signaling overhead based on a basic accesscontrol, while any other access in the future also allows for moredetailed configurations of the access control.

In accordance with a second embodiment, the DAC information may beprovided within each subsystem using resources assigned to thecorresponding subsystem. FIG. 11 shows the access control hierarchy inaccordance with the second embodiment with DAC information provided bythe respective subsystems. Other than in FIG. 10 , the BAC is providedusing resources allocated to the logical RAN for the anchor subsystem,while the DAC 102 _(x), 120 _(y) for the respective subsystems x and yare signaled using resources allocated to the logical RANs of therespective subsystems x and y.

In case a UE is to be connected to one or more of the subsystems, itreads the DAC of each of the respective subsystems. Alternatively eachsubsystem is mapped to an access category.

In accordance with an embodiment of the inventive approach, the DACs persubsystem may be scheduled in a time division multiplexing (TDM) fashionon different frequencies which allows the UE to receive the DAC using asingle receiver in a sequential manner which avoids the need toimplement multiple receivers at the UE that work on differentfrequencies in parallel.

In the following, an embodiment for acquiring the overall systeminformation in a wireless communication system, such as a 5G system isdescribed with reference to FIG. 12 . The process is performed once thebasic cell search and synchronization have been completed by a UE thatis about to connect to the wireless communication system. First, a MIB122 is acquired. The MIB 122 may contain basic configuration parameters,such as system bandwidth, system frame number, antenna configurationetc. Once the MIB 122 has been read, one or more essential systeminformation blocks 124, in the following referred to as essential SIB,are acquired. The essential SIB 124 includes the BAC 118 (see FIG. 10and FIG. 11 ). The acquisition of the system information may be complexand may take some time for the UE. The process may need to be repeatedregularly in each cell and after certain events, such as theinterruption of a connection, a re-establishment or the like. Theadvantage of splitting the access control into BAC and DAC is that theUE may access the system once the BAC has been successfully received viathe essential SIB 124. It is not needed to wait for all of the DACparameters forwarded by other SIBs 126 ₁ to 126 _(n). This speeds up theconnection set-up process and reduces the needed processing of thesystem information at the UE. For example, when the wireless system isin the first operation mode, for example, during a regular operation,the RAN resources are shared, and the UE may perform further connectionprocesses, like a RACH process, to connect to the base station once ithas read the essential SIB 124 which include the BAC 118. The other SIBs126 ₁ to 126 _(n) may not be transmitted as frequently as the essentialSIB 124, which is advantageous in situations of reduced or smallbandwidth capacities. Instead of waiting for all other SIBs 126 ₁ to 126_(n) to be scheduled eventually, the UE may already request thescheduling of specific SIBs via dedicated system information, forexample, using a SIB of a subsystem the UE decides to connect to.

Thus, as is shown in FIG. 12 , in accordance with embodiments of thepresent invention, the UE acquires the MIB 122 and based on theinformation obtained in the MIB 112, the UE decodes the essential SIB124 so as to obtain a first set of access control parameters (BAC). Incase the first access control parameter decoding is successful, the UEis allowed to access the system. In case the first access controldecoding fails, the UE is forbidden to access the system immediately,and the UE has to decode the other SIB 126 (at least those for thesubsystem to be accessed) including a second set of access controlparameters (DAC) before accessing the system. Using the DAC information,the base station may limit access to certain users, certain services orcertain subsystems as described above with regard to the first aspect.In case the second access control information decoding also fails, theUE is not allowed to access the system or the subsystem at all.

The inventive approach is advantageous in that, when the system is inthe first operation mode, like a regular operation, the UE may accessthe system more quickly by reading only the BAC information which, asexplained above, may be limited to only a few bits. Only in case ofcertain events, which cause the system to be operated in the secondoperational mode, the procedure involves reading the DAC parameters, forexample, for one or more of the subsystems, before the system may beaccessed.

In accordance with further embodiments, the inventive access controlscheme may be implemented to ensure highest reliability for a specificsubsystem. This is achieved by isolating resources used for signalingthe control information for a specific subsystem completely from theresources of the remaining subsystems. FIG. 13 is a schematicrepresentation for the isolation of control signals and channels forcertain subsystems, such as the PPDR subsystem #1. As is depicted inFIG. 13 , a system like in FIG. 3 is assumed. When the system is in thefirst operation mode, resources are shared among the respectivesubsystems which are to be accessed via the logical radio accessnetworks 114 ₁ to 114 ₄. The control information 116 for all subsystemsis transmitted using the resources of the anchor system #3. However, incase of a certain event or when the system, for other reasons, isoperating in the second operation mode, the inventive approach causes areconfiguration in such a way that isolated resources are used forsignaling the control information for one or more of the subsystems. Inthe embodiment of FIG. 13 , it is assumed that the PPDR subsystem #1 isto be isolated, for example, due to an emergency situation. In thiscase, dedicated control information 116′ is signaled on the respectiveresources for the PPDR subsystem #1 which is sufficient to provide for abasic means of communication, for example, for group calls for rescueforces during a disaster or the like.

To implement the embodiment of FIG. 13 , in accordance with furtherembodiments, the support of the subsystem #1 on the shared resources,such as the shared carriers, is stopped, and the subsystem #1 starts tooperate on the isolated, dedicated carriers. In accordance withembodiments, the decision to isolate a certain subsystem may be based onsystem load per subsystem over the air, for example, the number ofcertain UEs or certain types connected to a subsystem, the overall orper-user throughput per subsystem, etc., or the load of certainprocessing resources, for example, processing power or buffer filling,or certain transport resources, for example, the fronthaul or backhaulcapacity. A decision to isolate a certain subsystem may also be made bythe network side via an interface from the base station to the corenetwork or the operation and maintenance (O&M) center.

In accordance with further embodiments, before support of the PPDRsubsystem on the shared resources is stopped, the RRC layer may handover or redirect all active PPDR UEs, for example, RRC-connected UEs, tothe resources now used for the PPDR subsystem #1.

Third Aspect

The embodiments described so far concerned the acquisition of systeminformation in the downlink. After successful access control on thebasis of the information acquired in the downlink, the UE is ready toaccess the system, for example, via the random access channel (RACH) inthe uplink. FIG. 12 shows these additional steps for accessing thesystem. Following a successful acquisition of the system informationeither in the essential SIB 124 in case of a system operating in thefirst operating mode, or following the acquisition of the DACparameters, the RACH procedure 128 is initiated. Once the accessprocedure has been completed, further dedicated system information 130may be requested or obtained.

FIG. 14 shows a schematic representation of the respective logical radioaccess networks 114 ₁ to 114 ₄ in the downlink on the left (as in FIG. 3) and in the uplink on the right for the subsystems #1 to #4. In thedownlink, the control information 116 may be distributed as describedabove with regard to the first and second aspects. The base station mayallocate resources for a common RACH 132 for all subsystems or mayallocate resources for dedicated RACHs 134 ₁ to 134 ₄ for each of thesubsystems #1 to #4. In FIG. 14 , the common RACH 132 is shown as havingallocated therewith only resources of the logical RAN 114 ₃ of theanchor subsystem #3. The common RACH resource 132 may span resourcesallocated to a plurality of subsystems as the amount of resourcesinvolved may be significant. Dependent on the information provided bythe essential SIB 124, the UE may not be aware that multiple subsystemsare provided at this point of time. During the RACH process, asmentioned above with reference to FIG. 4 , collisions may happen andover-provisioning of resources is conventionally provided to limit theprobability of collisions. A system may be operated at 1 to 10% RACHload to have a small likelihood of collisions. However, this means that90 to 99% of the reserved RACH resources are wasted.

Embodiments of the present invention introduce an approach allowing theflexible use of the common RACH 132, the dedicated RACHs 134 ₁ to 134 ₄or a combination thereof, also referred to as a hybrid model.

For example, when the wireless communications system or parts thereofoperate in the first operation mode, e.g., during a regular operation,RACH overload is considered unlikely, and the common RACH 132 may beused. The common RACH 132 may be used differently by the one or more ofthe subsystems, dependent on subsystem specific parameters. For example,mMTC UEs may support a narrow-band RACH transmission with severalretransmissions, while eMBB or URLLC UEs use wide-band RACHtransmissions that are faster. Different UE types may use the sameresources; however, different radio parameters may be used. Theseparameters may be provided via system information or may be hardcoded bythe system standard, for example, a maximum bandwidth supported by mMTCUEs is defined to be 180 kHz (IoT devices), while eMBB UEs support abandwidth of 20 MHz or more. Other RACH parameters that may vary betweenthe subsystems, although the same RACH resources are used, may be asubsystem-specific RACH transmit power, RACH power increase parametersand repetition or backoff parameters.

In accordance with embodiments, the base station may monitor the load ofthe cell, for example, a number of connected UEs, an overall throughputor the PRB usage, as well as the load of the common RACH resources, forexample, based on the number of successful RACH receptions. Once theload exceeds a certain threshold, a high load situation may beidentified and the system may react in different ways. In accordancewith a first embodiment, if the common RACH resources are overloaded,the number of resources assigned for the common RACH 132 may beincreased. In accordance with another embodiment, the inventive accesscontrol described above may be actuated so as to restrict or bar any newaccess attempts by the UEs.

In accordance with an embodiment of the inventive approach, in a loadsituation the system may switch from providing the common RACH 132 forall subsystems to a system which uses dedicated RACHs 134 ₁ to 134 ₄, orthat uses a hybrid model using both the common RACH 132 and thededicated RACHs resources 134 ₁ to 134 ₄. For example, at high load, thebase station may decide to configure dedicated RACHs for one or more ofthe subsystems. All UEs from that subsystem starts using the dedicatedRACHs. The common RACH may be located in the anchor system, while thededicated RACH may be located within the other subsystem.

In accordance with further embodiments, when applying the hybrid model,the common RACH 132 may be used for an initial access only, and thededicated RACHs 134 ₁ to 134 ₄, may be used for UEs that have beenconnected already, for example, those UEs that have been configured witha dedicated RACH resource via the system information or that had enoughtime to read all the system information. Dependent on the establishmentcause of the RACH, for example, the kind of control signaling such asconnection set-up, connection re-establishment, handover, tracking areaupdate, the UE may use the common RACH or the dedicated RACH. Forexample, when the UE sends a RRC connection set-up message in a newcell, it may use the common RACH to access the cell or it may use thededicated RACH for a RRC connection re-establishment. In the first case,the dedicated RACH may not be known to the UE at this time as the systeminformation has not yet been received.

In another embodiment, the signaling of the resource indication of thecommon RACH may be part of the essential SIBs and the dedicated RACHresources may be signaled via the other SIBs at a later time and/or at adifferent frequency. This is schematically depicted in FIG. 15 showingthe acquisition of system information for the use of RACH resources.Initially, the MIB 122 is obtained followed by acquiring the essentialSIB 124. At a later point in time, the other SIBs 126 ₁ to 126 _(n) maybe obtained. In case the UE is able to access the system on the basis ofthe essential SIB 124, it uses the common RACH as is indicated at 128 a.Once the RACH procedure is completed, the dedicated system informationmay be requested as indicated at 130, and the UE may be informed that,for example, for a specific one of the subsystems or for all of thesubsystems dedicated RACHs may be used, as is indicated at 136.

In case access to the system on the basis of the essential SIB 124 isnot possible, the UE, as outlined above, obtains the other SIBs 126 onthe basis of which access to the system may be performed. If access ispossible, the UE is further signaled to use dedicated RACHs for theconnection set-up, as is indicated at 138. In this embodiment, the otherSIBs may include the additional information about the dedicated RACHs.

In terms of signaling overhead, it is advantageous if the signalingperiodicity of the essential SIBs, which include the information aboutthe resources for the common RACH, also referred to as common RACHresources, is higher than the signaling periodicity of the other SIBs126 ₁ to 126 _(n), which include the information about the resources forthe dedicated RACH, also referred to as the dedicated RACH resources.The UEs with time critical control information or service requests savestime as they may use the common RACH instead of the dedicated RACH.Further, more frequent signaling of the system information, due to theresource aggregation of multiple subsystems, the common RACH may have alarger resource pool than a dedicated RACH, i.e., the RACH resources arescheduled more often thereby reducing the overall latency fordelay-critical applications and services.

As mentioned above, UEs that use the common RACH to connect to the basestation may also request more system information via the dedicated RRCsignaling, for example, additional system information concerning thededicated RACH resource configuration or the configuration of anothersubsystem containing a dedicated RACH resource.

In accordance with further embodiments, the RACH preamble sequence spacemay be split, i.e., the common RACH resource may not make use of allpreambles, but certain preambles are set aside for the dedicated RACHresources. In a conventional RACH design (see 3GPP TS 36.211), there arealready different sets of preambles. A UE may select its preamblesequence dependent on the data quantity to be sent or based on itschannel quality. This concept may also be used for the respectivesubsystems when implementing network slicing.

In accordance with yet further embodiments, the essential SIBinformation is limited in that rather than explicitly indicating thecommon RACH resources in the essential SIB, for providing fast access,the existence of dedicated RACH resources is indicated, as is shown inthe table below.

Indicator Meaning eMBB Dedicated RACH existing/not existing URLLCDedicated RACH existing/not existing mMTC Dedicated RACH existing/notexisting PPDR Dedicated RACH existing/not existing

A specific service or a specific UE type may case the UE to the commonRACH or the dedicated RACH. For non-delay critical service types, the UEmay use the dedicated RACH, i.e., the UE waits until it knows thededicated RACH and until the time instance a RACH resource is scheduled.For example, when considering a PPDR subsystem, reliability is of higherimportance that the latency until a call is set-up. Therefore, althoughthe MIB and SIB are sent over resources allocated to an anchor subsystemwhich are shared with other subsystems, the dedicated RACH may beconfigured continuously so that the overall downlink control overhead isreduced while still providing highest reliability. The base station mayprovide the dedicated RACH resources at certain time intervals. The timeinterval may be either fixed for a certain slice with a default value,or may be altered via a message from the core network, e.g. O&M entitywithin the core network.

In accordance with further embodiments, the common RACH may not supportall RACH formats. For example, mMTC UEs or devices may operate indifferent coverage enhancement modes to provide deep indoor coverage.For such devices, an higher link budget is needed to connect to thesystem, and the common RACH are not optimized for providing an extremecoverage. To obtain the needed link budget an mMTC device may limit itstransmission bandwidth to concentrate its power to a small set ofresources. Furthermore, it may entail a large number of retransmissionsto connect to the system. While the common RACH resource may be used forthe basic coverage, the dedicated RACH resource may support some of theextreme coverage enhancement modes. In accordance with otherembodiments, there may be low complexity devices that havecharacteristics different from that of common devices and that may alsoneed dedicated RACH resources. Examples of such low complexity UEs maybe UEs with a single antenna, with half duplex only operation, withreduced transmission bandwidth and reduced processing capabilities,i.e., peak data rates.

In accordance with further embodiments, in specific situations it may bedesired to provide for a RACH resource isolation. For example, for PPDRsubsystems there may be known events when it is needed to isolateresources for the RACH process so as to allow for a reliablecommunication among the involved forces. In a similar way, at massevents, the load of the system may be high so that a RACH overloadcannot be excluded completely even when applying the inventive adaptiveaccess control. In such cases, some subsystems may use dedicated RACHresources in the uplink while they share resources in the downlink. Insuch a case the existence of a dedicated RACH resource may need to besignaled explicitly by the essential SIB.

In accordance with the embodiments described above, making use ofdedicated RACH resources which may be configured adaptively, the systeminformation needs to be updated accordingly. In accordance withembodiments, the UEs served by a base station may be notified about thechange of system information by a corresponding system informationchange notification and/or by respective value tags of the systeminformation. Once the UE has read the respective new system information,it starts to use the newly configured dedicated RACH resources.

In accordance with yet further embodiments, due to the differentrequirements of the different services provided by the respectivesubsystems, for example, in a 5G system, different RACH procedures fordifferent subsystems may be used. Besides, the above described four-stepRACH procedure, as it may be used in accordance with conventionalapproaches, such as the LTE approach, there may also be a two-step RACHprocedure for ultra-low latency services. FIG. 16 is a schematic view ofa two-step RACH procedure in accordance with an embodiment of thepresent invention. While in the conventional four-step proceduredescribed above, only a preamble is sent in the first message, inaccordance with the present embodiment, the two-step procedure shown inFIG. 16 already conveys first uplink information such as the UEidentity, a buffer status report and further first data in the firstmessage {circle around (1)}. This may be considered as a combination ofthe conventional messages {circle around (1)} and {circle around (3)} ina single message. In a similar way, the downlink response in the newmessage {circle around (2)} already contains the content resolution ofthe conventional downlink message {circle around (4)}.

In accordance with embodiments, the base station may configure differentRACH procedures for different subsystems, and the UE may first connectto the network using the conventional four-step RACH procedure on thebasis of the common RACH resources signaled in the essential SIB on theanchor subsystem. Once connected, the UE may obtain additional controlinformation via the other SIB. The additional control information maycontain the two-step RACH procedure. The physical RACH resources betweenthe conventional and the two-step procedure may be the same or may bedifferent resources.

Dependent on the UE's configuration or dependent on the configuration ofa subsystem, the UE may use either the two-step or the four-step RACHprocedure. For instance, a UE using URLLC services may use the two-stepRACH procedure once it is connected to the subsystem and configured. Insome subsystems, both procedures may be available for the same UE, andthere may be other criteria regarding which procedure is to be used. Forexample, the two-step RACH procedure may be used in a certain UE state,for example, the RRC inactive state. In accordance with otherembodiments it may be used for the transmission of small packets and thebase station may signal the size of the packet that can be transmittedvia the two-step RACH procedure. In accordance with yet otherembodiments, the two-step RACH procedure may be used to speed up certainRRC control messages, for example, a state transition from RRC inactiveto RRC connected.

In accordance with further embodiments of the present invention, theremay be different RRC states per subsystem. In a conventional system,such as the LTE system, a system only has two states, namely, RRCconnected and RRC idle, as is depicted in FIG. 17 schematicallyrepresenting an RRC state model for a wireless communication system,such as a 5G system. In the RRC connected state, the UE may transmit andreceive data via the shared channel. The UE has a UE identity and thelocation is known at the cell level. The mobility is handled by the basestation based on UE measurements. The state RRC idle is conventionallyused when there is no ongoing data transmission. The UE may only receivepaging in the downlink and may only use the RACH in the uplink toconnect to the system, and in this state, the UE is not known at the eNBor base station, does not have an UE identity and its location is knownat the paging area level. In accordance with the inventive approach,additional states are added, for example, the RRC inactive state. Thestate may be used to transmit infrequent small packets. The benefit isthat the UE does not have to go from the RRC idle state to the RRCconnected state for sending a small packet. In such a case the number ofcontrol messages to be exchanged and the size of the control data may belarger than the actual packet size.

In accordance with further embodiments of the present invention, the UEmay not use all of the existing states when being connected to a certainsubsystem. For example, a UE using the eMBB system may not need the RRCinactive state as there are no small packets to be transmitted. Eitherthe use of such states may be generally restricted for UEs using such asubsystem, for example, this may be implicitly hardcoded in thespecification for certain UE types or services, or some states may berestricted per subsystem on the basis the control information. Forexample, when considering a PPDR subsystem, the reliability is of higherpriority than power saving, and the PPDR subsystem may ask the UEs toremain in the RRC connected mode during a certain event, for example,during a mission critical operation, for a given time or generally. Thecontrol of the RRC state restrictions may be adaptive as part of the RRCbased on triggers from the radio access layers, or may be based oncertain load criteria or may be based on information obtained from thecore network or the operation and maintenance server.

Embodiments of the present invention may be implemented in a wirelesscommunication system as depicted in FIG. 2 including base stations,users, like mobile terminals or IoT devices. In accordance withembodiments, the user or the user equipment may be a device implementedinside a moving vehicle, like a moving vehicle, e.g., a car or a robot,or inside a flying device, e.g., an unmanned aerial vehicle (UAV) or aplane. FIG. 18 is a schematic representation of a wireless communicationsystem 200 for communicating information between a transmitter TX and areceiver RX. The transmitter TX may include one or more antennasANT_(TX) or an antenna array having a plurality of antenna elements. Thereceiver RX may include one or more antennas ANT_(RX). As is indicatedby the arrow 202 signals are communicated between the transmitter TX andthe receiver RX via a wireless communication link, like a radio link.The wireless communication system may operate in accordance with thetechniques described herein.

For example, the receiver RX, like a UE, is served by the transmitterTX, like a base station, and may access at least one of the logicalradio access networks of the wireless communication network. Thereceiver RX receives via the one or more antennas ANT_(RX) a radiosignal from the transmitter TX. The radio signal includes a controlsignal which indicates the physical resources of the wirelesscommunication network assigned to the logical radio access networkand/or access control information for the receiver RX for accessing thelogical radio access network. The receiver RX includes a signalprocessor 204 to process the control signal from the base station. Thetransmitter TX serves the receiver RX in the cell of the wirelesscommunication network having the plurality of logical radio accessnetworks. The transmitter TX communicates, via the one or more antennasANT_(TX), a plurality of users, like the receiver RX, to be served bythe base station for accessing one or more of the logical radio accessnetworks. The transmitter TX includes a signal processor 206 to generatethe control signal to selectively control the physical resources of thewireless communication network assigned to the logical radio accessnetworks and/or to control access of the users or user groups to one ormore of the logical radio access networks.

Although some aspects of the described concept have been described inthe context of an apparatus, it is clear that these aspects alsorepresent a description of the corresponding method, where a block or adevice corresponds to a method step or a feature of a method step.Analogously, aspects described in the context of a method step alsorepresent a description of a corresponding block or item or feature of acorresponding apparatus.

Various elements and features of the present invention may beimplemented in hardware using analog and/or digital circuits, insoftware, through the execution of instructions by one or more generalpurpose or special-purpose processors, or as a combination of hardwareand software. For example, embodiments of the present invention may beimplemented in the environment of a computer system or anotherprocessing system. FIG. 19 illustrates an example of a computer system300. The units or modules as well as the steps of the methods performedby these units may execute on one or more computer systems 300. Thecomputer system 300 includes one or more processors 302, like a specialpurpose or a general purpose digital signal processor. The processor 302is connected to a communication infrastructure 304, like a bus or anetwork. The computer system 300 includes a main memory 306, e.g., arandom access memory (RAM), and a secondary memory 308, e.g., a harddisk drive and/or a removable storage drive. The secondary memory 308may allow computer programs or other instructions to be loaded into thecomputer system 300. The computer system 300 may further include acommunications interface 310 to allow software and data to betransferred between computer system 300 and external devices. Thecommunication may be in the form electronic, electromagnetic, optical,or other signals capable of being handled by a communications interface.The communication may use a wire or a cable, fiber optics, a phone line,a cellular phone link, an RF link and other communications channels 312.

The terms “computer program medium” and “computer readable medium” areused to generally refer to tangible storage media such as removablestorage units or a hard disk installed in a hard disk drive. Thesecomputer program products are means for providing software to thecomputer system 300. The computer programs, also referred to as computercontrol logic, are stored in main memory 306 and/or secondary memory308. Computer programs may also be received via the communicationsinterface 310. The computer program, when executed, enable the computersystem 300 to implement the present invention. In particular, thecomputer program, when executed, enable processor 302 to implement theprocesses of the present invention, such as any of the methods describedherein. Accordingly, such a computer program may represent a controllerof the computer system 300. Where the disclosure is implemented usingsoftware, the software may be stored in a computer program product andloaded into computer system 300 using a removable storage drive, aninterface, like communications interface 310.

The implementation in hardware or in software may be performed using adigital storage medium, for example cloud storage, a floppy disk, a DVD,a Blue-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory,having electronically readable control signals stored thereon, whichcooperate (or are capable of cooperating) with a programmable computersystem such that the respective method is performed. Therefore, thedigital storage medium may be computer readable.

Some embodiments according to the invention comprise a data carrierhaving electronically readable control signals, which are capable ofcooperating with a programmable computer system, such that one of themethods described herein is performed.

Generally, embodiments of the present invention may be implemented as acomputer program product with a program code, the program code beingoperative for performing one of the methods when the computer programproduct runs on a computer. The program code may for example be storedon a machine readable carrier.

Other embodiments comprise the computer program for performing one ofthe methods described herein, stored on a machine readable carrier. Inother words, an embodiment of the inventive method is, therefore, acomputer program having a program code for performing one of the methodsdescribed herein, when the computer program runs on a computer.

A further embodiment of the inventive methods is, therefore, a datacarrier (or a digital storage medium, or a computer-readable medium)comprising, recorded thereon, the computer program for performing one ofthe methods described herein. A further embodiment of the inventivemethod is, therefore, a data stream or a sequence of signalsrepresenting the computer program for performing one of the methodsdescribed herein. The data stream or the sequence of signals may forexample be configured to be transferred via a data communicationconnection, for example via the Internet. A further embodiment comprisesa processing means, for example a computer, or a programmable logicdevice, configured to or adapted to perform one of the methods describedherein. A further embodiment comprises a computer having installedthereon the computer program for performing one of the methods describedherein.

In some embodiments, a programmable logic device (for example a fieldprogrammable gate array) may be used to perform some or all of thefunctionalities of the methods described herein. In some embodiments, afield programmable gate array may cooperate with a microprocessor inorder to perform one of the methods described herein. Generally, themethods are performed by any hardware apparatus.

While this invention has been described in terms of several advantageousembodiments, there are alterations, permutations, and equivalents whichfall within the scope of this invention. It should also be noted thatthere are many alternative ways of implementing the methods andcompositions of the present invention. It is therefore intended that thefollowing appended claims be interpreted as including all suchalterations, permutations, and equivalents as fall within the truespirit and scope of the present invention.

The invention claimed is:
 1. A device comprising: a communicationcircuit, wherein the communication circuit is arranged to communicatewith a plurality of user devices, wherein at least one of the pluralityof user devices is served by the device, wherein the least one of theplurality of user devices is provided access to a first portion of aplurality of logical radio access networks, wherein the first portion ofthe plurality of logical radio access networks comprises at least two ofthe plurality of logical radio access networks; and a control circuit,wherein the control circuit is arranged to selectively control a firstportion of the physical resources of a wireless communication network,wherein the first portion of the physical resources is assigned to thefirst portion of logical radio access networks, wherein the device isarranged to allow access to the at least one of the plurality of userdevices to the first portion the plurality of logical radio accessnetworks during a first operation mode, wherein the device is arrangedto adaptively limit access of the at least one of the plurality of userdevices to the first portion of the plurality of logical radio accessnetworks during a second operation mode.
 2. The device of claim 1,wherein at least one of the plurality of logical radio access networkscomprises at least one network slice, wherein an information controllingthe access of the user devices comprises an access class or an accesscategory.
 3. The device of claim 1, wherein the device is arranged togradually reduce the at least one of the plurality of user devicesallowed to access the first portion of the plurality of logical radioaccess networks.
 4. The device of claim 1, wherein the device isarranged to temporarily to bar access to the at least one of theplurality of user devices from the logical radio access network.
 5. Thedevice of claim 4, wherein the device is configured to signal to the atleast one of the plurality of user devices a barring time, wherein thebarring time indicates to the at least one of the plurality of userdevices when the at least one of the plurality of user devices shouldattempt to access the logical radio access network.
 6. The device ofclaim 4, wherein temporarily barring the first portion of the pluralityof logical radio access network comprises controlling the at least oneof the plurality of user devices to stay on the first portion of theplurality of logical radio access network and to signal to the at leasta second one of the plurality of user devices that access to the logicalradio access network is temporarily barred.
 7. The device of claim 1,wherein the device is arranged to temporarily bar access to the at leastone of the plurality logical radio access networks.
 8. The device ofclaim 7, wherein the device is configured to signal to the at least oneof the plurality of user devices a barring time, wherein the barringtime indicates to the at least one of the plurality of user devices whenthe at least one of the at least one plurality of user devices shouldattempt to access the logical radio access network.
 9. The device ofclaim 1, wherein selectively controlling the distribution of thephysical resources among the first portion of the plurality of logicalradio access networks comprises modifying number of physical resourcesallocated to the first portion of the plurality of logical radio accessnetwork.
 10. The device of claim 1, wherein selectively controlling thedistribution of the physical resources among the first portion of theplurality of logical radio access networks comprises limiting orsuspending at least one service using the first portion of the pluralityof logical radio access networks.
 11. The device of claim 10, whereinthe limiting or suspending at least one service using the logical radioaccess network the device comprises: selecting at least one of aplurality of user devices of a service using a service quality; andprioritizing the at least one of the plurality of user devices of thefirst portion of the plurality of logical radio access networks.
 12. Thedevice of claim 1, wherein selectively controlling the distribution ofthe physical resources among the first portion of the plurality oflogical radio access networks comprises increasing a scheduling priorityof at least one of the first portion of the plurality of logical radioaccess networks relative to at least one of a second portion of theplurality of logical radio access networks, or decreasing the schedulingpriority of at least one of a second portion of the plurality of logicalradio access networks relative to the scheduling priority of the firstportion of the plurality of logical radio access networks.
 13. Thedevice of claim 1, wherein the second operation mode is determined basedon a certain event, wherein the certain event is selected from the groupconsisting of a certain emergency situation, an overload situation of atleast a part of the wireless communication network, a need to balancethe load between the logical radio access networks, a need to providehighest resilience to one of the logical radio access networks, acertain event at a certain date and for a certain duration, changes in aservice using the logical radio access network, a certain day and/ornight time, and a schedule of certain reoccurring events.
 14. The deviceof claim 1, Wherein the wireless communication network is arranged toenable a plurality of instances for a logical radio access network,wherein the plurality of instances use different carriers, wherein thedevice is configured to redirect the at least one of the plurality ofuser devices to the carriers of another instance of the logical radioaccess network when at least one of the first portion of the pluralityof logical radio access networks is barred.
 15. The device of claim 1,wherein the device is arranged to selectively control a first portion ofthe physical resources using a common downlink system information orsignaling with a communication protocol, wherein the common downlinksystem information is provided by the wireless communication network forthe at least one of the plurality of user devices, the communicationprotocol is used by at least one of the plurality of logical radioaccess networks.
 16. The device of claim 15, wherein the device isarranged to signal control information to the at least one of theplurality of user devices whether a certain logical radio access networkis supported or is not supported by the wireless communication network,and/or limiting access to a logical radio access network to the leastone of the plurality of user devices, and/or barring access at least oneof the first portion of the plurality of logical radio access networks;and/or limiting access to specific service types of a service using thefirst portion of the plurality of logical radio access networks.
 17. Thedevice of claim 15, wherein the device is arranged to broadcast to theat least one of the plurality of user devices control information so asto indicate that additional access control information is acquiredbefore access, wherein the additional access control informationcontrols access of the at least one of the plurality of user devices toat least one f the logical radio access networks.
 18. The device ofclaim 15, wherein, the device is arranged to signal to a master user toconnect to slave user devices within the same coverage zone for acommunication using a device-to-device interface when access to alogical radio access network is blocked for a third portion of theplurality of user devices, wherein the master user is connected to thewireless communication network, wherein the slave user devices comprisea fourth portion of the third portion of the plurality of user devices.19. The device of claim 1, wherein the control circuit uses a controlsignal, wherein the control signal comprises a first set of accesscontrol parameters and a second set of access control parameters,wherein the device is arranged to broadcast the first set of accesscontrol parameters using the RRC protocol and the second set of accesscontrol parameters using the NAS protocol.
 20. A device comprising: acommunication circuit, wherein the communication circuit is arranged tocommunicate with a plurality of user devices, wherein at least one ofthe plurality of user devices are served by the device, wherein theleast one of the plurality of user devices is provided access to a firstportion of a plurality of logical radio access networks, wherein thefirst portion of the plurality of logical radio access networkscomprises at least two of the plurality of logical radio accessnetworks; and a control circuit, wherein the control circuit is arrangedto selectively control a first portion of the physical resources of thewireless communication network, wherein the first portion of thephysical resources is assigned to the first portion of the plurality oflogical radio access networks, wherein the device is arranged to allowaccess to the at least one of the plurality of user devices to the atleast one of the plurality of logical radio access networks during afirst operation mode, wherein the device is arranged to adaptivelyreduce the first portion of the plurality of logical radio accessnetworks during a second operation mode.
 21. The device of claim 20,wherein adaptively reducing the first portion of the plurality oflogical radio access networks comprises at least temporarily barring thefirst portion of the plurality of logical radio access network so as toincrease the available physical resources for a second portion of theplurality of logical radio access networks.
 22. The device of claim 20,wherein adaptively reducing the first portion of the plurality oflogical radio access networks comprises allowing access to a portion ofthe first portion of the plurality of logical radio access networks soas to increase the available physical resources for the at least one ofthe first portion of the plurality of logical radio access networks. 23.A method comprising: communicating with a plurality of user devices;providing access to at least one of the plurality of user devices to afirst portion of a plurality of logical radio access networks, whereinthe first portion of the plurality of logical radio access networkscomprises at least two of the plurality of logical radio accessnetworks; controlling a first portion of physical resources of awireless communication network, wherein the first portion of thephysical resources is assigned to the first portion of the plurality oflogical radio access networks; allowing access to the at least one ofthe plurality of user devices to the first portion of the plurality ofthe logical radio access networks during a first operation mode; andadaptively limiting access of the at least one of the plurality of userdevices to the first portion of the plurality of logical radio accessnetworks during a second operation mode.
 24. A computer program storedon a non-transitory medium, wherein the computer program when executedon a processor performs the method as claimed in claim
 23. 25. Acomputer program stored on a non-transitory medium, wherein the computerprogram when executed on a processor performs the method as claimed inclaim
 23. 26. A method comprising: communicating with a plurality ofuser devices; providing access to at least one of the plurality of userdevices to a first portion of a plurality of logical radio accessnetworks, wherein the first portion of the plurality of logical radioaccess networks comprises at least two of the plurality of logical radioaccess networks; controlling a first portion of physical resources of awireless communication network, wherein the first portion of thephysical resources is assigned to the first portion of the plurality oflogical radio access networks; allowing access to the at least one ofthe plurality of user devices to the first portion of the plurality ofthe logical radio access networks during a first operation mode; andadaptively reducing the first portion of the plurality of logical radioaccess networks during a second operation mode.